Thanks for that PDN, as it happens i have to go back there tommorrow as the pressure has dropped again, i suspect due to the PRV operating. However i think i will be stopping of at Halfords for pump and Tyre pressure guage. As it happens i'm guessing that those symptoms are not specific to glowworms as i have come across this a few times, if the pressure keeps rising the problem is that the EV has lost its air and just needs re-pressurising.
Thank again (if it works)
Bob the Plumber
February 2009